ISO 19115 Metadata for Air Quality

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ISO_19115_Metadata_for_Air_Quality Description: The metadata has the primary purpose to facilitate finding and accessing the data in order to help dealing with first two hurdles that the users face. Clearly, the air quality specific metadata such as sampling platform, data domain and measured parameters etc. need to be defined by air quality users. Dealing with the hurdles of data quality and multi-sensory data integration are topics of future efforts.

Glossary Domain: WCS

Related Links

Links to this page
http://en.wikipedia.org/wiki/ISO_19115

Create ISO Record - http://webapps.datafed.net/AQ_register.aspx

ISO 19115 Validator: http://webapps.datafed.net/xv.aspx?schema=http://ngdc.noaa.gov/metadata/published/xsd/schema.xs

ISO 19115/19119 Schema: http://ngdc.noaa.gov/metadata/published/xsd/schema.xsd

Contributors

Erin Robinson, CAPITA; Ted Habermann, NOAA; Wenli Yang, NASA; Chris Lynnes, NASA;

History

• Jan-May, 2009 First AQ Community Catalog Record Created
• May-August 2010 Worked with GEOSS AIP creating

Term Details

One of the goals of the AIP-II was to identify a GEOSS record that could be common for all Earth observations. The AQ group worked with the CCRM group to identify the key elements needed for discovery and create a standard metadata record that could be used by the community. For this the AQ WG used the ISO 19115 geographic information metadata standard to create the metadata records because it is the geospatial metadata standard recognized by GEOSS (2005) in the GEOSS Standard Registry (GEOSS, 2008) because it is open and internationally recognized. The ISO 19115 standard is also compatible with Catalog Service for the Web (CSW) standard interface with an ISO 19115 profile for dynamic querying (ISO 19115, 2005). The CSW and ISO 19115 Profile for CSW are also GEOSS recognized catalog service standards. Another benefit of the ISO 19115 standard is that it allows for not only discovery metadata to be included, but also includes data lineage, usage and other types of metadata for understanding multiple applications. The initial focus of metadata creation was on discovery however future work will include the extension of metadata to usage, lineage, and other components of the metadata. The discovery metadata record is defined as the minimum information a user needs to find the data and bind to it.

To identify the fields necessary for discovery of the metadata record we started with the ISO 19115 Core Metadata fields (Nogueras-Iso, 2005) and also the fields that were needed for a Catalog Service for the Web (CSW) Record. This fulfilled two goals – one to create valid ISO 19115 records and the other to be able to retrieve the records from the clearinghouse through a CSW 2.0.2 query. This list was compared to the current GEOSS Clearinghouses’ queryable and returnable fields. It was found that none of the clearinghouses or the GEOSS Service Registry allowed all of the CSW:record fields to be searched. It was also found that the three clearinghouses queried over different fields in the metadata record, there wasn’t a standard nomenclature for field names and key fields for Earth observation data, like temporal extent of the datasets, were missing.

Through the collaboration between the AQ WG and the CCRM WG, a key set of queryable fields for all Earth observations has emerged as a potential GEOSS Record: Dataset title, abstract, geolocation, temporal extent, keywords, service type, metadata file ID and associated component (catalog information). This set allows for text search as well as spatial and temporal searches. If a common vocabulary is used, additional keyword search allows discovery by measurement platform or observed phenomena. Information about the service type allows filtering by specific service standard and the associated component links the metadata record of a given dataset to a larger community catalog. These queryable fields can be in any metadata format, it is just important that the community agrees this set is needed to find any Earth observation service. With theGEOSS Record plus the ISO 19115 Core Metadata fields the AQ WG had a metadata record that could be used for discovery.